Total knee replacement is a surgical procedure to replace an inflamed or damaged cartilage or bone in the knee with an artificial joint when it is difficult to restore to a normal state, and includes processes of cutting both ends of the femur and tibia and implanting an artificial joint.
The conventional total knee replacement surgery has low precision because it involves cutting a patient's bone depending on a surgeon's experience and skills. To solve the problem, a cutting method using robots and a cutting method using optical infrared marker tracking is now widely used, and these methods involve a registration process for measuring a relative location between a target bone and a cutting device and a posture to increase the cutting accuracy and precision.
However, the registration process is not a process essential to achieving the primary purpose of surgery, i.e., cutting the real bone and implanting the artificial joint, and it is merely an ancillary process for helping achieve the purpose, but to improve the accuracy of surgery, it is inevitably performed through a complex procedure of about 15-20 minutes.
Registration is performed by indicating about 40 anatomical feature points of the femur and tibia using a probe, and in this instance, many errors occur, which often results in an incorrect registration result or registration failure.
During the registration process, the patient's knee joint is exposed through an incision, and the hazard of consequential secondary inflammation greatly increases and unnecessary bleeding continues. Furthermore, in the case of the cutting method using optical infrared marker tracking, one or two rods with infrared markers should be directly implanted into each of the femur and tibia of the patient, so there is a risk of fractures at the corresponding parts later.
Accordingly, there is a need for a new registration method that has a reduced error in registration, is convenient to use, and reduces the time it takes.